DUMB IDEA: Soldering paste as thermal compound?

[Hase]

So here is a dumb/interesting idea:

I got a ton of lead-free soldering paste lying around and I was wondering what would happen if I put that stuff between a CPU and heatsink, then put the heat-fan on there basically fusing the CPU and heatsink together.

If I won't fry the CPU maybe this turns out to be a decent thermal improvement. What are your thoughts?

[PCGuy_5960]

Don't do it. If you want something better than thermal paste, use liquid metal.

[k.m.p]

It may not be that bad of an idea, in fact it would fufill the role of creating a solid contact between the cpu heat spreader and the heat sink

 

That being said, do it at your own risk, you may destroy hardware, and I take no responsibility for broken hardware

[tp95112]

Well, you're going to need to make sure there are zero air pockets and its a very thin line of solder

[Hase]

Just now, PCGuy_5960 said:

Don't do it. If you want something better than thermal paste, use liquid metal.

Liquid metal can actually eat away on impure metals. I think I'll try regardless, not on something expensive, I have a Brasswell-something MiniPC sitting around somewhere. The thing has a passive heatsink. I was just wondering what you guys thought about the idea. It's more of a "will it even work" thought experiment.

[Vegetable]

Well basically as long as it makes good contact with both the CPU and the cooler, I'd see no reason as to why it wouldn't work. If nothing else it'd be like some really cheap thermal paste, or you could have discovered some new magic TIM and you're going to be rich here soon. 

[Billy_Mays]

Do you have an old system you don't care about do it on that then

[Enderman]

It won't help at all unless you bake it to melt the solder paste and join the CPU to the IHS.

At least 180C depending on the paste. You wont ever reach those temps by stressing the CPU.

I don't even know if intel uses a special paste when soldering their CPUs, so it may or may not work.

Worst case scenario you end up with a dead CPU.

 

The normal solution is to use liquid metal thermal compound, which is just as good if not better than solder.

[Hase]

Just now, Billy_Mays said:

Do you have an old system you don't care about do it on that then

Yeah thats the Idea, got like $99 mini Windows 10 PC sitting around and I use it for nothing really.

[Billy_Mays]

Just now, Hase said:

Yeah thats the Idea, got like $99 mini Windows 10 PC sitting around and I use it for nothing really.

Then try it on that

[Hase]

7 minutes ago, Enderman said:

It won't help at all unless you bake it to melt the solder paste and join the CPU to the IHS.

At least 180C depending on the paste. You wont ever reach those temps by stressing the CPU.

I don't even know if intel uses a special paste when soldering their CPUs, so it may or may not work.

Worst case scenario you end up with a dead CPU.

 

The normal solution is to use liquid metal thermal compound, which is just as good if not better than solder.

Well, if working on open components we use a heatgun (as stated in the original post) which goes up to around 220°C and melts the solderpaste on the parts. Alternatively you can put a soldering iron at about 250°C to the base of the heatsink and wait, same result. Baking the unit will only help to kill other parts of the computer.

 

Edit: also who goes for normal?

[Guest]

Do it

[Enderman]

2 minutes ago, Hase said:

Well, if working on open components we use a heatgun (as stated in the original post) which goes up to around 220°C and melts the solderpaste on the parts. Alternatively you can put a soldering iron at about 250°C to the base of the heatsink and wait, same result. Baking the unit will only help to kill other parts of the computer.

You could bake it if you solder the IHS to the CPU, like intel and AMD sometimes do.

If you try to heat to CPU to 200C with a massive heatsink on it you're not gonna get very far.

 

2 minutes ago, Hase said:

Edit: also who goes for normal?

People who want to do things the proper way without wasting money or killing hardware.

[Cyracus]

3 minutes ago, Enderman said:

People who want to do things the proper way without wasting money or killing hardware

screw that and screw them

[Hase]

25 minutes ago, Enderman said:

You could bake it if you solder the IHS to the CPU, like intel and AMD sometimes do.

If you try to heat to CPU to 200C with a massive heatsink on it you're not gonna get very far.

Not delidding the thing is the point, I know it works there. The word mini-pc should tell you that the sink is not massive.

[The Benjamins]

1 hour ago, Hase said:

So here is a dumb/interesting idea:

I got a ton of lead-free soldering paste lying around and I was wondering what would happen if I put that stuff between a CPU and heatsink, then put the heat-fan on there basically fusing the CPU and heatsink together.

If I won't fry the CPU maybe this turns out to be a decent thermal improvement. What are your thoughts?

it would work as long as you have low temp solder (90c-100c or lower) so you can get it to liquefy at crazy high OC/over volt and then run the CPU lower so it is under that.

The key would be to get it to initially melt and to sand away the finish off the CPU and block so it is a copper finish to allow for adhesion.

[Bananasplit_00]

well. good luck with this, go get a P4 and motherboard so you dont destroy something thats actiually usefull lol

[Hase]

16 minutes ago, Bananasplit_00 said:

well. good luck with this, go get a P4 and motherboard so you dont destroy something thats actiually usefull lol

Read my answers, I have a Brasswell-something MiniPC sitting around that I use for notihng. It's literally a tiny one board Windows PC with a 2 inch heatsink on it.

 

If and only if that works I might move on to something a little bigger in the future.

[System Error Message]

if you wish to solder what you do is heat up the heatsink. Use a solder that melts at a much lower temperature but melt it by putting the heatsink on and heating the heatsink. Make sure to put strands of solder around the cpu towards the center but not enough for it to overspill.

 

a lot of people dont get that putting too little paste is bad for the CPU regardless of type, this is because the more paste that makes contact between the IHS and heatsink, the better the heat transfer will be as heat transfer is all about surface area and thermal contact. However in the case of metal paste you cant put too little or too much. Putting too much thermal paste is not harmful and i've done it a number of times. The extra paste will just fall out the side but if its not conductive it is fine.

 

When you take out a heatsink after its been on for a while, if you see the paste around the center of the chip only that means that too little has been placed.

 

Lead free or lead full solder doesnt matter. CPUs will be fine up to 200C but the safe way to do this is to put a ball of solder on the center of CPU, put the heatsink on, heat the heatsink and let the heatsink melt the solder down. You can keep the CPU cool by having another piece of metal attached to the IHS to take the heat away from the IHS to reduce the heat onto the CPU. Dont keep the heat on for too long, do it in stages.

[Bananasplit_00]

3 minutes ago, Hase said:

Read my answers, I have a Brasswell-something MiniPC sitting around that I use for notihng. It's literally a tiny one board Windows PC with a 2 inch heatsink on it.

 

If and only if that works I might move on to something a little bigger in the future.

you should probably make sure to use the defult text color because i didnt realize there was more then "read my answers" untill i quoted. anyway i might do this to one of my poor P4's just because

[Hase]

4 minutes ago, System Error Message said:

if you wish to solder what you do is heat up the heatsink. Use a solder that melts at a much lower temperature but melt it by putting the heatsink on and heating the heatsink. Make sure to put strands of solder around the cpu towards the center but not enough for it to overspill.

This is exactly what I was planning

4 minutes ago, System Error Message said:

a lot of people dont get that putting too little paste is bad for the CPU regardless of type, this is because the more paste that makes contact between the IHS and heatsink, the better the heat transfer will be as heat transfer is all about surface area and thermal contact. However in the case of metal paste you cant put too little or too much. Putting too much thermal paste is not harmful and i've done it a number of times. The extra paste will just fall out the side but if its not conductive it is fine.

Luckily I am aware, been in the business for a while

4 minutes ago, System Error Message said:

Lead free or lead full solder doesnt matter. CPUs will be fine up to 200C but the safe way to do this is to put a ball of solder on the center of CPU, put the heatsink on, heat the heatsink and let the heatsink melt the solder down. You can keep the CPU cool by having another piece of metal attached to the IHS to take the heat away from the IHS to reduce the heat onto the CPU. Dont keep the heat on for too long, do it in stages.

I think I'll be fine going at it with a soldering iron moving around on top of the heatsink. It's easy to see when the solder melts. I can control the heat output of my iron to the degree between 90-310°C.

I think it should work, most of the solder is rated at 180°C and below.

I buy the lead-free shit for health reasons mostly, solder smoke is bad enough as it is.

[System Error Message]

Just now, Hase said:

This is exactly what I was planning

Luckily I am aware, been in the business for a while

I think I'll be fine going at it with a soldering iron moving around on top of the heatsink. It's easy to see when the solder melts. I can control the heat output of my iron to the degree between 90-310°C.

I think it should work, most of the solder is rated at 180°C and below.

I buy the lead-free shit for health reasons mostly, solder smoke is bad enough as it is.

just make sure the solder you use doesnt melt at too low a temperature. Ideally you want it close to 200C but below. This is because you want to avoid the solder melting if the CPU gets too hot as if it melts more it could overspill.

 

I know you can control the heat of the iron but damage to components isnt really about temperature, its about the energy applied. So you solder in stages, melt it bit by bit allowing for cooling between each time.

[Hase]

7 minutes ago, Bananasplit_00 said:

you should probably make sure to use the defult text color because i didnt realize there was more then "read my answers" untill i quoted. anyway i might do this to one of my poor P4's just because

I thought I was using the default text color?  I just made my account here and did not change any settings.

 

Anyways sounds good, I'll be sure to post my findings including benchmarks by the end of the week

[Hase]

Just now, System Error Message said:

just make sure the solder you use doesnt melt at too low a temperature. Ideally you want it close to 200C but below. This is because you want to avoid the solder melting if the CPU gets too hot as if it melts more it could overspill.

 

I know you can control the heat of the iron but damage to components isnt really about temperature, its about the energy applied. So you solder in stages, melt it bit by bit allowing for cooling between each time.

Indeed, I was thinking of going from the center of the heatsink to the outside and pausing in between, in order to allow byproduct gas buildup to dissipate.

[ssd512]

On 7/25/2017 at 12:06 AM, k.m.p said:

It may not be that bad of an idea, in fact it would fufill the role of creating a solid contact between the cpu heat spreader and the heat sink

 

That being said, do it at your own risk, you may destroy hardware, and I take no responsibility for broken hardware

have you tried??I'm thinking about to buy some flux to use it as thermal paste